Machines for the provision of corrugated sheet-like elements made of various materials, to be used for example for packaging or for thermal insulation or soundproofing, are currently known.
Conventional machines usually comprise two chain conveyors, or shaping elements, which move along a closed path a plurality of transverse flaps or bars also known as rods.
In the background art, as disclosed in EP1620253B1 by the same Applicant, these rods are moved into the working position by a dedicated mechanism.
Specifically, the transverse flaps of each conveyor provide a sort of comb. The flaps of one conveyor face, in the working or the formation area of the corrugated sheet-like element, the rods of the other conveyor, being intercalated between them. The sheet-like element is therefore pushed by the flaps of the two conveyors, which, being mutually intercalated, press the sheet-like element, providing the typical “wavelike” deformation of said element.
Conventional machines further comprise means for joining the corrugated sheet-like element thus obtained to one or more other flat sheet-like elements, at the peaks of the provided corrugations, in order to provide a composite structure.
The machines of the known type are not devoid from drawbacks. In particular, at the end of the joining process, the rods are still inside the corrugation and must be extracted from said corrugations by means of a complex mechanism that allows their outward movement, parallel to the corrugation. An additional mechanism must then return the rods to the working position, so that they can be used again to provide the sheet-like corrugated element. The movement of such rods, therefore, occurs in a direction that is substantially transverse to the direction of motion of the corrugated material and therefore entails a considerable reduction of the production rates as well as a considerable and expensive mechanical complication.
Moreover, said rods are a severe limitation to the size of the corrugations of the sheet-like element, since their thickness cannot be reduced below a correct size.